Mophie is already pretty well known for its battery pack cases, but its freshly launched Space Pack also adds extra internal storage for your iPhone.

Launched today at CES 2014, the Mophie Space Pack is designed to work with the iPhone 5 and the iPhone 5s and is available with an additional 16GB or 32GB of storage. In addition to providing storage, it also claims to double the battery life of the devices, providing a whole recharge from flat.

There’s also an accompanying (free) iOS app for navigating that storage and managing files in a familiar, native-like interface.

The original Mophie Juice Pack wasn’t, and still isn’t, the cheapest on the market (costing between $80 and $110), so adding additional storage unsurprisingly increases the overall cost. The 16GB version is available to pre-order now for $149.95, while the 32GB version costs $179.95. Both models are due to ship in March.

It’s still not the cheapest, but running out of storage on your iPhone and having to delete photos, videos, apps or music is the second most annoying thing to a flat battery, so if you’re in the market for a battery booster it might be worth considering.